Box forming apparatus



Dec. 18, 1962 F. c. GROSS BOX FORMING APPARATUS 5 Sheets-Sheet 1 Filed Sept. 16, 1959 INVENTOR. FRANK C. GQO$S ATTOQNEY Dec. 18, 1962 F. c. GROSS 3,068,760

BOX FORMING APPARATUS Filed Sept. 16, 1959 5 Sheets-Sheet 2 INVENTOR. FPANK C. GQOSS ATTOQNEY Dec. 18, 1962 F. c. GROSS BOX FORMING APPARATUS 5 Sheets-Sheet 3 Filed Sept. 16, 1959 INVENTOR. FQANK C -GI20$S BY w ATTORNEY Dec. 18, 1962 F. c. GROSS 3,068,760

BOX FORMING APPARATUS Filed Sept. 16, 1959 s Sheets-Sheet 4 INVENTOR. FRANK C. GQOSS ATTOQNEY Dec. 18, 1962 F. c. GROSS 3,068,760

BOX FORMING APPARATUS Filed Sept. 16, 1959 5 Sheets-Sheet 5 &

IN V EN TOR.

FQANK C. GRCBS ATTOQNEY United States Patent Ofi 3,058,760 Patented Dec. 18, 1952 ice 3,068,760 BOX FORMING APPARATUS Frank C. Gross, 863 Ridge Road, Wilbraham, Mass. Filed Sept. 16, 1959, Ser. No. 840,396 24 Claims. (Cl. 93-49) a carton blank to final form as an erected carton while Y subjecting same to various heat-sealing and pressuresealing operations.

The invention resides in the construction, arrangement, location and relationship of the various elements, components and instrumentalities of the carton forming apparatus, as exemplified in the detailed disclosure hereinafter set forth and wherein the objects of the invention, as defined in the paragraphs below, will be apparent.

Broadly speaking, the invention envisions a heat sealing carton former which forms a heat sealed carton from a scored carton blank by folding the blank along score lines and heat sealing variously arranged side and end walls or panels and glue tabs thereof together by applying heat and pressure thereto.

It will be helpful to an understanding of this invention to first briefly consider some of the more important objects and features and aspects thereof, so that same may be kept in mind during the subsequent reading of the de-' tailed description of the practical embodiments herein disclosed.

Initially, it is to be noted that the principles of my invention may be embodied in any carton forming apparatus and/or maybe incorporated as a carton forming station in any. carton filling or packaging machine.

An essential point. of the present invention lies in the provision of a new and novel method of forming and sealing permitting the use of a simple mechanical mandrel operation. The invention embraces broadly the concept of a reciprocating forming mandrel which in a single cycle makes an inward stroke and an outward retrograde stroke. The mandrel, serving as a prime mover, coacts with a spring loaded bottom plate and an associated pair of combination end folder and sealing plates which travel in and out with the mandrel, they being actuated thereby.

It is a principal object hereof to provide an inventively novel and improved construction of the type defined in which a carton forming apparatus has a capacity for applying heat and pressure at points where a seal is to be made in the course of carton erection and during the inand out travel of the forming mandrel.

The construction incorporates a pair of self-aligning combination end folder and sealing plates which are juxtaposed and hinged to a spring-loaded or floating bottom plate so as to be traversable therewith as an assemblage or sub-assembly. This sub-assembly coacts with the forming mandrel as same moves inwardly and outwardly in its carton-erecting motions.

The invention envisions the preheating of certain of the panels of the carton for efiectuating the heating of the heat sealable spots thereon, the folding of the carton end panels and glue tabs, the folding of the carton side panels, and the rotating of the glue tabs into position prior to the pressure sealing, all as sequential steps in a method of carton erecting.

Another object hereof is to provide an apparatus whereby the aforedescribed sequential steps may be successfully carried out.

It is another object hereof to provide a floating forming mandrel, and an assemblage of bottom and end plates which is self-alignable relative thereto, so as to offer a correct registration of the carton blanks therewith and an equalization of the sealing pressure at the end plates at the opposite ends of the bottom plate.

The carton envisioned for use in connection herewith preferentially carries spot coatings or overall coatings of a heat-sealable medium on certain surfaces of certain of its panels which may be subjected to heating and pressure sealing during certain of the sequential steps in the carton-erecting operation whereby the fully erected end product is fully sealed in certain contacting and permanently-bonded areas or portions thereof.

Heating elements for eflecting same are suitably positioned on the end folder and sealing plates hingedly connected to the bottom plate and constituting therewith a subassembly to facilitate the application of heat from the outside of the carton being erected. Heating elements may also be suitably positioned, if desired, on the forming mandrel so as to facilitate the application of additional heat from the inside of the carton.

If desired, the end folder and sealing plates may be heated by stationary bars in addition to or in lieu of the heating elements referred to above. The stationary bars may be so disposed that the said plates rest thereon when the apparatus is in the rest or non-operating position.

As will appear, it is a purpose hereof to provide, in the case of spot coated carton blanks as differentiated from over-all coated blanks, heat and pressure sealing elements not only adjacent certain of the outside surfaces of the carton blank but also adjacent certain of the inside surfaces thereof, all so as to accelerate the heat sealing 3 action and to lend to high erection speeds.

The invention envisions the direct heating of a surface 'ofa panel of a carton by means of disposing said surface immediately adjacent the heating element and it also envisions the indirect heating of a surface of a carton panel indirectly by means of disposing the heating element adjacent the opposite side of the panel and forcing the heat to pass therethrough to said surface. The latter is essential where a heat sealing medium is employed on the panel surface so as to make direct contact thereof by the heating element obviously inadvisable.

Another chief object of the invention is to provide a carton forming apparatus wherein the required heat sealing time is shortened due to a preheating feature wherein the carton blank or parts thereof may be heated prior to the initiation of the folding and sealing operations.

A unique design of combination end folder and sealing plates hingedly connected to and floating with a springloaded bottom plate as an assemblage facilitates this preheating of portions of the carton preliminary to the folding and pressure sealing and permits the forming operations and the heating and sealing phases thereof to take place during a part of both the inward and outward travel of the forming mandrel. During the in travel, successive periods of preheating and heating and sealing are provided. During a portion of the out travel, a continuous period of heating and sealing is provided.

It will be added here that the heating and pressure sealing means are easily adjustable so as to provide versatility to the apparatus, it being easily convertible and adaptable to any one of a wide range of desired operating conditions.

In contradistinction, the known prior art devices invariably necessitate longer heat sealing times in their operational use.

As a further and most salient feature, the self-aligning capability of certain of the components hereof, identified as the floating assemblage, facilitates the equalizing of the heat sealing pressure on both ends of the carton blank during carton erection, the components being free to ad just transversely relative to the main axis of movement of the forming mandrel. I

As another chief feature, the spring-loaded bottom plate precludes bowing of the bottom panel of the carton and, in coaction with the associated side and end panel actuators, minimizes the bowing of the carton side aud/or-end panels, during erection. Same insures the formation of a carton which is more square and with less bowing of the side and/ or end panels thereof than has been possible to attain with known prior art carton form ing constructions.

In addition to the practical advantages which I have herein ascribed to my novel carton forming arrangement, it will be observable that another chief feature hereof, made possible by the use of the aforedescribed spring-loaded assemblage, resides in its capability of discharging an erected carton from substantially the location of the carton blank immediately prior to the initiation of the erecting process, The arrangement does not operate on the principle of thrusting or pushing a formed carton through a forming section to the opposite side thereof, a principle well known in the prior art. Rather, this invention operates on the principle of returning a formed carton to a point adjacent that where the carton blank is initially disposed before erection. Thus, the length of the forming stroke required for the forming mandrel is appreciably reduced, a particularly desirable feature in the formation of cartons having hinged covers, and the speed of operation is thereby accelerated so as to offerpossibilities of increased production, while at the same time, carton formation at a minimum velocity is assured. This unique discharge feature additionally leads to a higher rate of discharge of formed cartons to the production line, and'an improved degree of control thereover.

Additionally, by means of the unique design of end folder and sealing plates and of simultaneously functioning side forming means, it is possible to eliminate the scuffing of surfaces and the smearing of printers ink on the cartons in operational use. By means hereof, the panels of the carton blank are movable with their respective folding elements in greater degree than has heretofore been possible in prior art devices where the cartons being formed and the elements accomplishing the forming move relative to each other so as to exhibit increased tendencies to scuif or otherwise injure carton surfaces and to cause smudging or smearing of any printing thereon. In this invention, the carton being movable with the folding elementsof the apparatus as it is, there is noticeably less opportunity for surface scufling of the cartons and/or smearing of any printing carried by the cartons.

All 'of the above objects I accomplish in the course of providing an apparatus which necessitates a minimum of floor space, which is of simple, yet fool proof, opera 7 tion allowing a single operator to serve more than a single machine, and which dispenses with the handling of obviously objectionable adhesive materials on the production line, thereby eliminating the necessity of cleaning and maintaining such subassemblies as adhesive applicators, glue pots or the like.

Other of the chief objects and purposes hereof are to provide advantageous structural and operational features in a device having the following inherent meritorious characteristics: first, a' simplicity in construction and therefore an adaptability to economical manufacture; second, a uniqueness in engineering design of coacting parts wherefor the components are coordinated for facile assembly and/or installation which when once assembled and/or installed are positively and securely retained in operative relationship; third, a flexibility or capability of adjustment by which a large variety of work can be produced by means of the same device; fourth, a high degree of efficiency and dependability in its operational use; and fifth, the provision of such other improvements in andrelating to carton forming apparatus as are hereinafter described and claimed.

'Further objects hereof are to provide a construction conformable to the desiderata of the preceeding paragraph and offering specific improvements in the various operating instrumentalities comprising same leading to its distinctiveness in appearance, compactness in design, practicalness in value, and durableness in organization.

With these and other objects and advantages in view, some of which will be in part'obvious or in part pointed out more fully hereinafter, all will become apparent as the detailed description of the exemplary forms of the invention intended to be protected by Letters Patent proceeds below.

It will be obvious, to those skilled in the art to which the invention pertains, that same may be incorporated in any one of many different constructions.

It is to be understood that the physical embodiments and the structural details thereof described and illustrated are only indicative of but several of the various ways, albeit the preferred ways, in which the principles of the invention may be employed and in which the component parts may be combined and arranged. However, said embodiments are not intended to be exhaustive of, nor limiting of, the spirit hereof. The precise constructions of the figures of the drawings need not be slavishly followed as, of course, various components may reasonably and understandably have to be modified in accordance with any specific use to which it isto be put. Stated otherwise, the objects are susceptible of attainment by use of constructions differing in certain respects from that disclosed, all without departing from the underlying principles hereof.

It is premised, accordingly, that adaptations and/ or modifications are comprehended within the range of equivalence of the below subjoined claims, there being no intent to have the invention limited to or circumscribed by any specific details, of size, form, proportion, material, and the like, being limited only by the priorart and the scope of the appended claims.

The advantages hereof as outlined are best realized when all of its features and instrumentalities are combined, but useful embodiments may be produced involving less than the whole and it will, be borne in mind, in the reading of this specification and the claims which fol low, that all of the recited. components need not necessarily be present in a single apparatus in order to satisfy the spirit and scope hereof.

The novel features which I'consider as characteristic of my invention, as to its principles of design and operation, and as to its construction and organization, will be best understood from a consideration of the following detailed description. I a

In'the drawings, forming a part of this description, like characters of reference or numerals are employed to designate like or corresponding parts throughout the several views.

In said drawings:

FIG. 1 is a side elevational view of the carton forming apparatus of my invention shown in the open position;

FIG. 2 is a plan view of the apparatus shown in FIG. '1;

FIG. 3 is a side elevational view similar to the view in FIG. 1, but showing the apparatus in the closed position;

FIG. 4 is a fragmentary side elevational view of an end folder and sealing plate and of the'forming mandrel and of related components for purposes of more clearly illustrating details of the invention;

FIG. 5 is a fragmentary sectional view toward the end folder and sealing plate shown in FIG. 4 for purposes of further illustrating features of the invention; FIG. 6 is a broken side elevational view of the lower portion of a forming mandrel and a bottom plate showing a modified form of the mating components; 1 FIG. 7 is a broken end elevational view of the structure showninFlG. 6; V

FIG. 7A is a broken side elevational view, similarto FIG. 6, showing still another modified form of the mating components;

FIGS. 8-11 are perspective views of a part of a carton blank in a progressive series showing the sequential steps in the folding of the end panels, glue tabs and side panels relative to the bottom panel thereof;

FIG. 12 is a full perspective view of a fully erected carton showing a cover panel and dust flap associated therewith, same being of the type included in the carton blank illustrated in connection with FIGS. 1-3; and

FIGS. 13-16 are perspective views of a carton blank in a progressive series showing the sequential steps in the folding of the end panels, glue tabs and side panels relative to the bottom panel of said carton blank wherein the glue tabs are disposed outwardly of the end panels with FIGS. 13-15 showing only a part of a carton and with FIG. 16 showing a full view of the carton.

In said detailed description and in the claims therefollowing, various details are identified by specific names for convenience. These names however are intended to be as generic in their application as the art will permit.

With continued reference now to the drawings, which illustrate a typical embodiment of the invention for the purpose of disclosure and form a part of this specification, I have provided figures of simplified and semi-diagrammatic form, showing the essentials as advantageously incorporated within a specific apparatus in order that the general relationship of components and their interaction may be better understood, with certain of the components being omitted from certain of the figures for purposes of further simplification.

It will be understood, of course, that the apparatus can be elaborated to whatever extent desired.

For instance, while I have shown a device designed to be operated by an overhead forming mandrel, it will be evident that the apparatus may be caused to operate under the influence of any suitable prime mover through appropriate connecting means.

Likewise, I have not shown herein any means for positioning the carton blanks on the so-called operating table of the apparatus. Such positioning can be accomplished by hand, if desired, or by means of a feed hopper or the like for said blanks, which feed hopper may be of any of the known styles, equipped for feeding the blanks one by one onto the operating table of the device, either in timed sequence or as required by the operator.

Likewise, I have not shown herein any means for removing the erected carton from the operating table. Such discharge may be accomplished by hand or by suitable mechanical discharge means.

The apparatus, shown in FIGS. 1-3, includes a horizontally-disposed platformincluding a pair of spaced, parallel disposed members and 10 connected by and mounted upon a plurality of frame members 12 for purposes of supporting same.

It will be here stated and made clear that, Whereas in said FIGS. 1-3 the components are shown in a generally horizontally disposed-position relative to a base or flooring above which the apparatus is supported, it is entirely conceivable that apparatus where the components are generally vertically-disposed or otherwise angularly disposed may be employed to meet specific operating conditions, such as the nature of the machinery with which the apparatus may desirably be employed, the nature of space restrictions within which the apparatus may be set up, et cetera. That is, the apparatus has been designed with such eventualities being fully borne in mind so that it is equally well adapted for a so-called horizontal disposition, a so-called vertical disposition, or a disposition other than either. i

Members 10 and 10 support a pair of spaced, paralleldisposed members 16 and 16 extending transverse to the longitudinal axis of said members 10 and 10 at the midsection thereof and secured rigidly thereto by a pair of apertured plates 17. One of said plates 17 bridges the outer surfaces of members 16 and 16; the other of said plates 17 bridges the outer surfaces of members 10 and 10. The plates 17 of the pair thereof are secured to each other by means of bolts 18 extendable therethrough and through the aligned members 10 and 10 and 16 and 16.

Members 10 and 10 coacting with the members 16 and 16 will be understood to comprise the so-called platform of the apparatus. Said platform may beof any, other construction compatible with the purpose of my invention and the term platform will be understood to be envisioned herein in its strict generic sense. i

The adjacent ends of members 16.and 16 aresuitably interconnected by a spring housing assembly comprising a spring sleeve 20 having a flangemember 22 enclosing same approximately at themidsection thereof and secured thereto as by a weldment, press fit, or other .convenient and known means. Said flange member 22 seats upon and is secured to the respective ends of members 16 and 16 of the pair thereof as by weldments, bolts, or other suitable means. I y

Each spring housing assembly additionally includes a coil spring 26 disposed within the spring sleeve and having an upper extremity in hooked engagement with a transversely-extending pin 28 extendable through opposite sides of said spring sleeve, and further having a lower extremity in hooked engagement with a spring pin or eye bolt 30-threadedly engaged with a foot member 34 and secured thereto as by nuts 36. Said nuts function not only to secure the spring number 26 but also to provide an adjusting means therefor.

Foot member 34 may be of channelled stock or of other suitable configuration so as to extend between the opposite sides of the apparatus distantly of and in parallelism with spaced members 16 and 16. I

In FIG. 3, the lower portion of the spring 26 to the viewer is shown.

Centrally of foot member 34, I provide a: central shank 40 (see FIG. 3) which is extendable through the aligned central oversized openings 17 inthe plates 17 and 17 and is fixed to foot member 34 by any suitable means- The walls of openings 17' are provided with radii and the openings themselves are somewhat larger than central shank 40 to facilitate the flotation of the central shank relative thereto. p

On the platform, adjacent opposite ends thereo'f, -.I mount brackets 50 and 50. Each bracket has adepe nding foot portion centrally thereof and extendable between spaced members 10 and 10 to permit the sliding adjust ment of the bracket upon and'relative to members 10 and 10 for serving carton blanks of dilferent dimensions, the bracket being secured in a desired position along and relative to members 10 and 10 by means of a bolt 52 and washer 54, or equivalent means. g a

An elongated lever 60 is receivable within a slot or recess 62 in the bifurcated forward face of the bracket, is pivot-ally mounted at 64 thereto and carries a pressure roll 66 rotatably mounted thereonat 68 and receivable within the slot provided at the bifurcated extremity thereof. V

Slot 62 is of such dimension as to permit varying degrees of rotative travel of lever 60 therewithin, upon its pivotal mounting 64, and against the action of a springloading mechanism bearing against an inclined face at one end of the lever. Said spring-loading mechanism comprises an adjustable bolt threadedly engageable with bracket 50 and having a spring 82 sleeved therearound and disposed between the head of the bolt and the said inclined face of the lever. The adjustment of bolt 80 serves to increase or to decrease the compression of spring '82 against the inclined face of the lever. See FIG. 3.

An adjustable stop screw having a nut 92 on its inner end extends transversely through and is threadedly engageable with lever 60. Adjustment of said stop screw toward and away from the inner face of slot 62 of bracket 50 effects the amount of free travel of lever 60 relanearest tive to bracket 50 and, in coaction with the adjustable spring-loading mechanism at one end of the lever, serves to vary the spring loading and positioning of pressure roll at the opposite extremity of the lever relative to its mating component hereinafter to be described.

A pair of secondary transverse members 100 and 100 extend between the sides of the apparatus in parallelism with and spaced outwardly of members 16 and 16. Each is secured to a stub projecting forwardly from the forward face of a bracket 50 and is secured thereto as by bolts 102 or the like. See FIG. 3.

Upon each member 100, a pair of cam members 110 are slidably mounted so as to be disposed in a plane forwardly of the plane of the forward face of the related bracket 50.

The cam membersware slidably adjustable along their respective secondary transverse member 100 for purposes of accommodating different sizes of carton blanks.

A bottom plate or platen 120 is supported distantly from the platform by means of central shank 40, the adjacent extremity thereof being fitted to bottom plate 120 andsecured thereto as by a pair of socket head cap screws 122 or equivalent means. As aforesaid, the opposite extremity of the central shank is fitted to said f ot member 34 as by screws, bolts, or the like.

Said. bottom plate 120 is a floating member in th sense that it is self-aligna'ble as it is urged inwardly, by a means yet to be described. As it is so driven, central shank 40 is likewise directedginwardly so as to depress foot mernber 34 against the spring action of the pair of spring housing assemblies fixed to member 16 and 16 at the opposite ends thereo and on opposite sides, of the central shank. Spring members of said spring housing assemblies are tensioned by the movement of foot member 34 wherefor a spring-loaded characteristic of bottom plate 120 is attained.

The selfalignability of the bottom plate 120 is a desirable feature offering to the plate a freedom of shifting movement laterally or in a direction transverse to its in and out movement of travel as well as in the said direction of in and out travel. The spring mounting has floating characteristics, as will 'be observable, so as to permit the bottom plate and related components to be motivated by and to be centralized relative to a reciprocating forming mandrel hereinafter to be described. That is, the selflig ing feature permits the bottom plate to move in the in and out direction of travel with the in and out travel of the forming mandrel and to be simultaneously shi'ftahle in directions transverse to the axis of the said in and out travel wherefor the bottom plate can shift as necessity may dictate to align itself relative to the bottom face of the forming mandrel.

The spring-loaded, floating, bottom plate precludes bowing of the bottom panel of a carton during the erecting process and accordingly makes possible the production of a carton which is more square and with less bowing of-its side and end panels.

At opposite sides of bottom plate 120, pairs ofv laterally-spaced side forming rollers 130 are provided. Same are shown as formed by a solid shaft provided with an nndercut 132 centrally thereof. It will be understood, however, that any conventional form of shaft and roll design may be adopted with equivalent ease. For in stance, a side forming rollershaft may be employed which carries suitably journalled rotatable side forming rolls.

Each side-forming roller arrangement is rotatably supportedv upwardly in a plane which is disposed below the plane of the bottom plate 120 by means of a side for-ming roller bracket 134. Said bracket has an extremity engageable with the shaft in undercut 132 in such manner as to permit the rotation of the shaft androllers' 130 thereof relative thereto.

The opposite extremity of bracket 134 is provided with anenlarged base 136 having shoulders on one surface at 8 opposite ends thereof for seating upon the faces of and permitting bridging between members 16 and 16.

A plate member 142 is disposed adjacent and bridges members 16 and 16 in alignment with said base 136 and is secured thereto in such manner as to clamp members 16 and 16 therebetween by means of a bolt 144 extending through one of and being threadedly engageable with the other of members 136 and 142.

Bracket 134 is slidably adjustablerelative to members. 16 and 16 so as to be movable therealong, again for the stated purpose of accommodating carton blanks of different dimensions.

As best shown in FIG. 2, at each end of bottom plate 120, a combination end folder and sealing plate assembly is hingedly connected thereto. An end folder and sealing plate 150 has a pivotally mounted camming member 170 secured centrally thereof to its outermost face, as by screws or the like. a

The camming member 170 is preferably made of plastic or like insulating material and is provided with an innermost centrally disposed offset extension or tang 171 through which a transversely-extending hinge pin 152 is extendable.

Outwardly extending ears 121 of plate 120, at opposite ends and adjacent opposite sides thereof, are provided with means for the reception of the opposite end portions of the adjacent hinge pin 152 wherefor a hinged connection between member 120 and camming member 170 is attained through a clevis arrangement.

Plate member 150, serving as a heating member as will subsequently appear, is not directly connected to the plate'120.

Said hinge pin 152 is loosely fitted in the appropriately aligned openings of camming member 170 and bottom plate 120, the openings being oversized so as to offer the respective end folder and sealing plate a self-aligning characteristic. 7

As shown in FIG. 1, the opposed camming members 170 at opposite ends of the bottom plate 120 are interconnected by means of a pair of and folder plate springs 160 disposed therebetween astride central shank 40. Each said spring is engageable at its opposite extremities with a spring pin or spring stud 162 projecting outwardly from its respective camming member 170 secured to the central portion of the outermost face of its respective end folder andsealing plate 150.

Said's'prings 160 have a capacity for urging the innermost or uppermost faces of the opposed end folder and 7 sealing plates to lie disposed in a plane coplanar with the plane of the uppermost face of bottom plate 120 in the V non-operative position of the apparatus wherefor the carton blank may be easily placed in juxtaposition therewith.

Each end folder and sealing plate is provided with a pair of finger slots on opposite sides of camming member 170 for the receptiontherethrough of glue tab aligning fingers 182. See FIG. 2.

Each said finger 182 has an inner end provided with a hub 184 fixed to one end of its respective glue tab finger shaft 186. Said shaft 186 has fixed to its opposite end the hub of a lever 188 having a cam follower roll 190 rotatably mounted on its opposite and outer free end. 7

The cam follower roll will subsequently be observed to be engageable with its respective. cam 110. r

The outermost face of the camming member 170 se cured to said end folder plate 150 is relieved on its opposite sides so as to provide a raised camming'portion throughout the length of its midsection having a general configuration comprising a forming dwell 172, a pressure lobe 174, and a sealing dwell 176 therealong.

Pressure roll 66 will subsequently be observed to be rollable therealong, same functioning asa cam surface and providing the requisite dwell time during the in and out travel of the forming mandrel and the bottom plate and end folder and sealing plates actuated thereby.

Cartridge heaters 200, or electrodes for dielectric sealing or other equivalent heating means, are disposed in appropriate cavities within each end folder and sealing plate 150. As shown, same are disposed adjacent and on opposite sides of camming member 170. It will be understood of course that same might be otherwise relatively disposed. For example an additional cartridge heater might be disposed centrally of said plate 150.

It will be further understood that appropriate energization and control means will be associated with each said heating element. Same are not shown herein for purposes of simplification.

As an additional and/ or alternative method of heating the end folder and sealing plate 150, I have shown in FIGS. 1 and 2 only, and only on the left side of the apparatus in each case, a heater bar 400 which may be so positioned relative to the member 150 as to permit said member 150 to lie disposed in a plane coplanar with the plane of the uppermost face of bottom plate 120 in the non-operative position of the apparatus wherefor the carton blank may be easily placed in juxtaposition therewith.

The heater bar 400 may be supported by means of a bracket 402 fixed to each bracket 50 to which brackets 402 the bar 400 may be secured as by screws or the like, being separated therefrom by means of insulators 405.

The heater bar comprises a heater block which is appropriately cavitized so as to receive heating elements 406 therewithin. Again, it is to be explained that appropriate energization and control means will be associated with the heater bar, and that same are not shown herein for purposes of simplification.

Magnetic inserts 408 of the permanent magnet type may be receivable within the heater bar 400 so as to offer .upper faces which are coplanar with the upper surface of the heater bar and are adapted to coact with magnetic inserts suitably aligned relative thereto and disposed in the lower face of the respective end folder, and sealing plate so as to establish good contact therebetween to insure good heat transfer in the heating of the folding and sealing plates 150 during their normal position of rest.

A suitably supported forming mandrel or arbor generally indicated by 210 and having an outwardly extending shank 212 is arranged for reciprocatory movement centrally of the apparatus hereof, and has an innermost face of substantially the same shape as the bottom panel of the carton to be formed.

The forming mandrel may be of any construction compatible with the purpose of my invention.

Cartridge heaters 220, or electrodes for dielectric sealing, or equivalent means, may be provided in suitable cavities in "mandrel sealing faces 214 disposed at and separated from the mandrel body per se 216 by insulated bridges 218. See FIG. 1.

Again, it will be understood that appropriate energization and control means will be associated with each said heating element.

In FIG. 2, I have illustrated by dash lines the general outline of a paper board carton blank C for the setting up of which the apparatus hereof is designed. The said blank be made by the usual operations of cutting and scoring paperboard or box board which may be printed as desired.

The blank will normally comprise a bottom panel to which end panels and side panels are articulated along score lines. The side panels have articulated thereto at their opposite outer end edges glue tabs. The end panels may have articulated thereto at their outer end edges tapered dust flaps. To one of the side panels, which in effect is the back wall of the carton, may be articulated a cover panel having articulated thereto at its outer side edge a tuck flap.

As shown in a series of sequential steps in the carton erection method according to this invention, FIGS. 8-12, the carton envisioned for use may be erected from its form as a blank where all parts are coplanar; first, as in FIG. 8, by swinging end panels 302 at opposite ends of bottom panel 300 and glue tabs 304 at opposite ends of each of side panels 306, to almost vertical positions with respect to bottom panel 300; second, as in FIG. 9, by urging glue tabs 304 inwardly upon their hinge connections with the respective side panels so as to be vertically disposed and forward of the plane of the adjacent end panels; third, as in FIG. 10, by folding side panels 306 at opposite sides of bottom panel 300 in such manner that glue tabs 304 are rotated therewith forwardly of the inner face of the end panels 302 adjacently disposed therebetween; and fourth, as in FIG. 11, by completing the folding of end panels 302 and heat sealing to bring about the interengagement of the outer faces of the glue tabs and the inner faces of the related end panels. The completed fully erected carton is shown in FIG. 12 showingha cover panel 308 and a tuck flap 310 associated therew1 Whereas a carton having straight side and end walls, that is walls which are disposed at an angle of degrees relative to the plane of the bottom wall, is herein shown, it is envisioned that said side and end walls may be otherwise angularly disposed at angles less than 90 degrees for the attainment of cartons having so-called tapered walls, all within the spirit hereof.

The apparatus of this invention performs all of the folding operations in a series of sequential steps-in a single operation or cyclic movement thereof.

The initial stage of the erecting operation is shown in FIGS. 1 and 2 where the components are shown in their relative open position before the actuation of forming mandrel 210.

Features of the subsequent stage of the erecting operation are shown in FIGS. 4 and 5 where cartain components are shown with forming mandrel 210, partially directed inwardly.

In FIG. 3, the next stage of the erecting operation is shown where the components are illustrated in the relative closed position with forming mandrel 210 in its innermost position. I As indicated in FIGS. 1 and 2, carton blank C is initially disposed upon bottom plate with bottom panel 300 overlying same in such manner that forming mandrel 210 will subsequently contact said bottom panel.

End panels 302, glue tabs 304 and side panels 306 are coplanar with bottom panel 300 and overlie other components of the apparatus as will be observed.

Each side panel 306 overlies the respective side forming rolls 130. Each end panel 302 overlies the respective end folder and sealing plate with glue tabs 304 adjacent each end panel overlying the respective glue tab aligning finger in the then non-operative position beneath the respective end folder and sealing plate, as best understood by reference to FIG. 1.

As forming mandrel 210 is actuated inwardly toward bottom plate 120, with the carton blank juxtaposed therebetween, it embraces the bottom panel of the carton.

As will best be observed by reference to FIGS. 4 and 5, read in the light of FIGS. 8-11, the carton blank wherein all parts thereof are initially coplanar is first acted upon by the swinging of the end panels 302 at opposite ends of the bottom panel 300 and the swinging of the glue tabs 304 at opposite ends of each of the side panels 306 to nearly upright positions with respect to said bottom panel 300. Said end panels and adjacent glue tabs are urged in a folding manner along their respective hinge lines toward their afore-described upright positions by the action of the respective end folder and sealing plates disposed outwardly thereof.

Secondly, the glue tabs 304 are deflected further inwardly by the action of the respective glue tab aligning fingers 182 so as to be inclined slightly forwardly of the plane of the adjacent end panel 302. Said fingers maintain the position of the respective glue tabs sufficiently per fingers (not shown).

11 long as to insure the engagement of the glue tabs with the associated end panels as referred to below.

Thirdly, the side panels are urged toward their upright positions by the action of the side forming rollers which are disposed on the outside of the respective side panels in such manner as to urge the side panel in a folding manner along its respective hinge line adjacent the respective edge of the bottom panel. Simultaneously therewith, the respective glue tabs are rotated so as to swing therewith forwardly of the inner face of the adjacent end panel 302 in such manner as to lie disposed adjacent the respective end face of the forming mandrel wherefor the carton assumes a fully erected position as the forming mandrel completes the inward stroke of its cycle.

Fourthly, the carton, having been fully erected, the

forming mandrel continues its in travel followed by its out travel so that the interengagement of the outer faces of the glue tabs and the inner face of the related end panel is brought about during the pressure and sealing phases of the operation. It is hereto be emphasized that a preheating operation may take place when and as the carton blank is placed in juxtaposition with the bottom plate and the end folding and sealing plates and as the folding of the end panels and glue tabs and side panels of the carton blank is initiated.

By this method, the surfaces of the glue tab are being heated for subsequent intimate contact with the glue pattern or a portion of the overall coating, as the case may be. Such method does not depend entirely upon the driving of the heat through the carton blank.

The sealing operation takes place during portions of both the in and out travel of the mandrel.

With reference to'FIG. 4, as the forming mandrel travels inwardly, the cam follower roll 190 actuating the glue tab aligning finger 182 contacts the related cam face of its respective cam 110 and the pressure roll 66 contacts .the related cam face of its respective camming member 170 at the beginning of the forming dwell.

vWith the continued in travel of the forming mandrel, erection of the carton iscompleted. As will be observed in FIG. 3, pressure roll '66 rides along the pressure dwell of its respective camming member.

The heating time of the end panelsand glue tabs in their operation is represented as the total time during which the pressure roll 66 is in engagement with the cam face of its respective camming member during the forming portion of the in travel of the forming mandrel and during the out travel thereof.

As shown in FIG. 4, as the pressure roll rides in the forming dwell of its respective cam face, the respective glue tab aligning fingers 182 are urged inwardly so as to urge the glue tab inwardly along its respective fold line so as to be inclined slightly forwardly of the plane of the adjacent end panel.

Being thus urged forwardly and as its related side panel is subsequently urged into its upright position concomitantly, the effect is to rotate the glue tabs therewith forwardiy of the inner face of the adjacent end panel between the end panel and the complementary face of the forming m nd By, the heat sealing means, the interengagernent of the outer-face of each glue tab and a portion of the inner face of the related end panel is realized.

The side and end panels are folded uprightly to posi-' ,tions angular to the bottom panel of the carton blank and the glue tabs are folded inwardly adjacent portions of the inside wall of the respective end panel.

When the forming mandrel is released and withdrawn outwardly, the now-erected carton travels with the forming mandrel until acted upon by suitably positioned strip- Itis to be here noted that the apparatus hereof does not push the formed carton through the forming section,

in eontradistinction from most prior art devices, but rather returns it to a point distantly of the forming section for discharge therefrom, all to the end that the length of the stroke required for the forming mandrel is appreciably reduced, a feature especially advantageous in the case of formed cartons incorporating hinged covers.

The outward movement of the forming mandrel results in the movement outwardly of the bottom plate -so as to lead to the release of the end folder and sealing plates and the resumption of their normal position coplanar with the bottom plate, under the influence of the end folder plate springs. Thereupon, the bottom plate comes to its outermost position and the continued outward movement of the forming mandrel frees the erected carton, by virtue of the suitably positioned stripperfingers. Suitable mechanism may be provided for discharging the carton in the fully erected condition, shown in perspective in FIG. 12, from the apparatus.

By the unique arrangement hereof, it is to be appreciated that I provide a mechanism wherein the heat and pressure sealing function is performed during a portion of both the in and on travel of the forming mandrel,

and wherein the end folder and sealing plates are hinged to the bottom plate and are self-alignabletherewith so as to travel with the carton while it is being formed and sealed and to permit the equalization of the heat-sealing pressure exerted upon the respective end panel of the carton.

Additionally, it is to be understood that a pre-heating time is achieved hereby, each end folder and sealing plate serving to. heat the end panel and the adjacent glue tabs of the carton blank preliminary to and as the said carton components are being swung into the fully folded erected position, all so as to reduce or shorten the actual total sealing time required.

In FIGS. 6 and 7, a modified form of certain components of the invention is shown and here described.

The operating surface of the bottom plate 120 may be provided with an outwardly-facing convex face 121 and the mating operating surface of the forming mandrel '210 may be provided with an inwardly-facing concave face 211.

Such cooperating faces, when a carton blank C is disposed therebetween, insure the over-breaking of the said blank along the score lines so as to insure regularity in the shape of the carton. This is accomplished by overbending a portion of the bottom panel of the blank beyond degrees so that a momentary distortion in said bottom panel is advantageously tolerated without any concomitant overbending of the end or side panels wherefor a more squarely erected carton is attained.

Also, if desired, the bottom wall of the forming mandrel and the matching bottom panel may be simlarly provided with other than a planar surface. Reference will now be made to FIG. 7A.

It is entirely conceivable that thecomplernental surfaces. of the bottom plate 120 and the forming mandrel 210" may be provided with marginal portions 121" and 211" which may be angularly disposed relative to the normal plane of the mating face of the bottom plate.

The mating face of the forming mandrel 210 may be relieved in its center .as shown :at 213", all so as to offer cooperating faces which, when a carton blank C is disposed therebetween, insure the over-breaking of the said blank along the score lines beyond 90 degrees soas to insure regularity and squareness in the shape of the carton. V I

As another feature of the invention and if it is so desired, the cam" members may be suitably adapted by means of additional cam lobes, to serve the function of actuating the respective glue tab aligning fingers 182 in such manner as to bring about a like momentary overbreaking or overbending of the respective glue tab beyond 90 degrees, the said glue tab thus overbent being shown in dash lines in FIG. 8, to the end that bowing is further minimized, if not eliminated, in the successful erection of a fully square carton.

It will be understood that it is within the spirit and scope of this invention that by suitable modification of certain instrumentalities hereof, the end panels of the carton blank may be caused to swing inwardly of the glue tabs, rather than vice versa as recited, by means of appropriately disposed fingers, wherefor the glue tabs will be formed outside of, rather than inside of, the end panels. Of course, in such instance, the heat scalable spots or coating on the blank will be appropriately positioned so as to accommodate the modified situation.

Such a carton is shown in the modified series of sequential steps in the carton erection method illustrated in FIGS. 13-16. The modified carton envisioned for use may be erected from its form as a blank where all parts are coplanar; first, as in FIG. 13, by swinging end panels 302' at opposite ends of bottom panel 300' and glue tabs 304 at opposite ends of each of side panels 306, to nearly vertical positions with respect to bottom panel 300'; second as in FIG. 14, by urging end panels 302' inwardly upon their hinge connections with the bottom panel so as to be vertically disposed and forward of the plane of the adjacent glue tabs 304; third, as in FIG. 15, by folding side panels 306' at opposite sides of bottom panel 300' in such manner that glue tabs 304 are rotated therewith outwardly of the outer face of end panels 302' adjacently disposed; and fourth, as in FIG. 16, by completing the folding of glue tabs 304 and heat sealing to bring about the interengagement of the inner faces of the glue tabs and the outer faces of the respective end panels.

The preheating of the outer faces of certain panels prior to their intimate contact with the heat sealing media on the inner faces of the glue tabs, which glue tabs have been preheated simultaneously by virtue of driving heat through the board stock from the opposite or outer faces thereof is a key feature of this invention.

The total heating time includes the preheating period which may commence when the blank is placed in position upon the bottom plate and before the folding operations actually ensue and the heating period which commences on the inward stroke of the forming mandrel and bottom plate.

Further this invention contemplates any suitably arranged glue pattern involving the side and end panels and the so-called glue tabs, it being obvious that a multiplicity of arrangements of contacting panels and tabs is possible, it not being desired to be limited to the specific exemplification shown.

It will be understood that in the event that the carton blank employed utilizes glue tabs articulated to the opposite ends of each of the end panels rather than the side panels as herein'above described, it is entirely within the spirit and scope hereof that this apparatus may be accordingly modified, all in such manner as to produce means for articulating said glue tabs into operative positions in the same contemplated manner. That is, the glue tabs are foldable and rotatable regardless of whether they are articulated to the side or end panels.

In other words, while herein reference has been made to end folder and sealing plates hingedly connected to and movable with the bottom plate and side forming roller members disposed adjacent the bottom plate, same has been namely for purposes of reference and orienta tion, it being entirely conceivable that the side panels and the roller members may serve the end panels of a carton being erected.

Although my invention has been described and illustrated herein with particular reference to specific carton forming structures, it should be appreciated that its utility and application extend beyond the particular types illustrated and its broad scope and concept comprehend the useful and novel features set forth when combined with 14 any type of carton forming mechanism and thus, with respect to the scope of the invention, the foregoing material is to be considered as illustrative rather than limit- The invention is susceptible of various modifications and alternative constructions, and it is to be understood that I do not thereby intend to limit the invention to the specific forms above disclosed, but intend to cover all modifications, variations, altemative constructions and equivalents reasonably falling within the spirit and scope of the invention as expressed in the appended claims and within the meaning and purview and range of equivalents of this disclosure.

I claim:

1. In a machine for forming during a carton-erecting operating cycle an erected carton from a flat blank of a type scored to provide a bottom panel with pairs of opposite end panels and opposite side panels articulated to the edges of the bottom panel for erection upwardly relative thereto and pairs of glue tabs articulated to one of the pairs of panels for erection upwardly relative to the bottom panel and simultaneous rotation inwardly relative to the respective panel of the other of the pair of panels for interengagement therewith, said machine comprising, a support means, a forming mandrel serving as prime mover, a self-alignable resiliently-mounted blank-supporting assemblage comprising a bottom plate and an end panel and glue tab folding plate hingedly connected to the bottom plate at each end thereof, a pair of pivotable spring-loaded levers each adjustably secured relative to said support means at one of the opposite ends of said assemblage, a pressure roll rotatably mounted on each said lever, a cam means secured to each end panel and glue tab folding plate of said assemblage for coaction with the respective said pressure roll, the end panel and glue tab folding plates and bottom plate of said assemblage being traversible upon actuation from a normal non-operative position in directions linear with the main axis of and according to the movement of said mandrel away from and toward the non-operative position and being simultaneously traversible in lateral directions generally transverse to the main axis and with the end panel and glue tab folding plates of said assemblage being foldable with respect to the bottom plate of Said assemblage by the action of said pressure rolls upon the respective said cam means of the end panel and glue tab folding plates of said assemblage.

2. In the machine as set forth in claim 1, including, a pair of side panel folding elements fixed to said support means, one side panel folding element of said pair thereof being disposed adjacent each side of the bottom plate of said assemblage.

3. In the machine as set forth in claim 1, including, glue tab rotating means operable simultaneously with the concomitant travel of said assemblage and prime mover.

4. In the machine as set forth in claim 1, including heating means associated with the end panel and glue tab folding plates of said assemblage.

5. In a carton-erecting machine for forming during a carton-erecting cycle an erected carton from a flat blank of a type scored to provide a bottom panel with pairs of opposite end panels and opposite side panels articulated to the edges of the bottom panel for erection upwardly relative thereto and pairs of glue tabs articulated to one of the pairs of panels for erection upwardly relative to the bottom panel and for rotation inwardly relative to the respective panel of the other of the pair of panels for interengagement therewith, said machine comprising, a support means, a reciprocating forming mandrel, a self-alignable resiliently-mounted assemba e for supporting said blank and being movable therewith and comprising a bottom plate and an end panel and glue tab folding plate pivotally connected to the bottom plate at. each end thereof, a pivotably spring-loaded lever adjustably secured relative to said support means at each of the opposite ends of said assemblage, a pressure roll rotatably mounted on each said lever, a cam means secured to each end panel and glue tab folding plate of 'said assemblage for coaction with the respective said pressure roll, the end panel and glue tab folding plates and the bottom plate of said assemblage being traversible from a normal position of rest with said blank in directions linear with the main axis of and according to the movement of said mandrel away from and toward the normal position of rest and being simultaneously traversible in lateral directions generally transverse to the main axis upon simultaneous yielding movement of said levers and respective pressure rolls and wtih the end panel and glue tab folding plates of said assemblage being pivotable with respect to the bottom plate of said assemblage by the action of said pressure rolls upon the cam means of the respective end panel and glue tab folding plates of said assemblage for simultaneously folding and erecting a pair of opposite end panels and associated glue tabs of said blank.

6. In the carton-erecting machine as set forth in claim 5, including, glue tab aligning means mounted upon and movable with the movement of the end panel and glue tab folding plates of said assemblage for deflecting the glue tabs of the blank in planesforwardly of the planes of the related end panels of the blank.

7. In the carton-erecting machine as set forth in claim 5, including, aligning means mounted upon and movable with the movement of said end panel and glue tab folding plates of said assemblage for deflecting the end panels of the blank in planes forwardly of the planes of the related glue tabs of the blank.

8. In a carton-erecting machine for forming during a carton-erecting cycle an erected carton from a flat blank of a type scored to provide a bottom panel with a pair 'of opposite primary panels and a pair of opposite secondary panels articulated to the opposite edges of the bottom panel for erection upwardly relative thereto and pairs of glue tabs articulated to one of the pairs of panels for erection upwardly relative to the bottom'panel and for rotation inwardly relative to the respective panel of the other of the pair of panels for interengagement therewith with certain of the panel surfaces being conditioned with a heat sealable medium for effectuating interengagemerit of the panels of one of the pairs thereof with the respective glue tabs, said machine comprising, a support means, a reciprocating forming mandrel, a self-alignable resiliently-mounted assemblage for supporting said blank and being movable therewith and comprising a bottom plate and a primary panel and glue tab folding plate'pivotally connected to the bottom plate at each end thereof, a pivotable spring-loaded lever adjustably secured relative to said support means at each of the opposite ends of said assemblage, a pressure roll rotatably mounted on each said lever, a cam means secured to each primary panel and glue tab folding plate of said assemblage for coaction with the respective said pressure roll,- the primary panel and glue tab folding plates and the bottom plate of said assemblage being traversible from a normal position of rest'with said blank in directions linear with the main axis of and according to the movement of said mandrel away from and toward the normal position'of rest and being simultaneously traversible in lateral directions generally transverse to the main axis upon simul- '-taneousl yielding movement of said levers and respective pressure'rolls and with the primary panel and glue tab folding plates of said assemblage being pivotable with respect to the bottom plate of said assemblage by the action of said pressure rolls upon the cam means of the respectiveprimary panel and glue tab folding plates of said as semblage'for simultaneously folding and erecting a pair of'opposite primary panels and associated glue tabs of saidblank.

9. In the machine as set forth in claim 8, including, secondary panel folding means juxtaposed adjacent the bottom plate of said assemblage for simultaneously effecting folding of the secondary panels and rotation of the glue tabs of the blank during the concomitant travel of said assemblage and mandrel.

10. In the machine as set forth in claim 8, including, a heating member integral with each of the primary panel and glue tab folding plates of said assemblage for heating certain panels and glue tabs of the blank during the travel of said assemblage and mandrel.

11. In the machine as set forth in claim 8, including, a

heating member integral with each of the primary panel and glue tab folding plates of said assemblage for preheating certain panels and glue tabs of the blank preliminary to the travel of said assemblage and mandrel and for preheating certain panels and glue tabs of the blank during the simultaneous folding thereof at the initial phase of the inward travel of said assemblage and mandrel and for heating and sealing certain panels and glue tabs of the blank during the final phase of the inward travel and the initial phase of the outward travel of said assemblage and mandrel.

12. In the machine as set forth in claim 8, including, stationary heating means fixed to said suppo'rt'means at each of the opposite ends of said assemblage for transmitting heat to each of the primary panel and glue tab folding plates of said assemblage with said assemblage being disposed in the normal position of rest.

13. In the machine as set forth in claim' 12, including, magnetized elements associated with said stationary heating means and attracting the primary panel and glue tab folding plates of said assemblage to the respective of said heating members.

14. In the machine as set forth in claim 8, including,

heating elements integral with said mandrel for the heating of certain of the panels of the blank during the reciprocating movement of said assemblage and mandrel.

16. In the machine as set forth in claim 8, including the bottom plate of said assemblage being provided with an outwardly-shaped face and said mandrel being provided with a complemental inwardly-shaped face for effectuating the over-breaking of the bottom panel of the blank along the score lines adjacent the bottom panel during the entirety of the travel of said assemblage and mandrel.

17. In the machine as set forth in claim 8, including, adjustment means associated with said spring-loaded levers and associated pressure rolls relative to saidassemblage and mandrel for varying the positioning thereof in ac commodating carton blanks of different sizes. 7

18. In the machine as set forth in claim 9, including,

adjustment meansassociated with said secondary panel folding means for varying the positioning of said secondary panel folding means relative to said assemblage and mandrel in accommodating carton blanks of different sizes.

19. In the machine as set forth in claim 9, each said cam means including a contoured cam surface positioned for camming Contact with its respective said pressure roll and configured for eifectuating during the reciprocation 'of said assemblage and mandrel a forming dwell in the a posite end panels and a pair of opposite side panels atticulated to the opposite edges of the bottom panel for erection upwardly relative thereto and pairs of glue tabs articulated to one of the pairs of panels for erection upwardly relative to the bottom panel and for rotation inwardly relative to the respective panel of the other of the pair of panels for interengagement therewith with certain of the panel surfaces being conditioned with a heat sealable medium for eifectuan'ng interengagement of the panels of one of the other pairs thereof with the respective glue tabs by an arrangement including a continuously reciprocating forming mandrel and a work supporting assembly of a bottom plate and a pair of opposite panel and tab folding and sealing plates hingedly connected to and traversable with the bottom plate recipr-ocable therewith, the latter by the former, with the blank being held between and movable with the mandrel and assembly in a timed relationship according to the movement of the mandrel through an initial and a final phase of movement, that method of preheating and folding and heating and pressure sealing the carton blank during the continuous reciprocating motion which comprises, the sequential steps of, preheating a pair of opposite panels and tabs. of the blank preliminary to and during the initial folding of the first named panels and tabs of the blank, simultaneously folding and heating the first named pair of opposite panels and tabs of the blanks and folding the other of the pairs of opposite panels of the blank in timed relation therewith and simultaneously rotating the preheated and prefolded tabs therewith and relative to the preheated first named panels of the blank into a completely-erected heat-sealing position during the initial phase of the cycle, and simultaneously heating and pressure sealing the preheated and prefolded and prerotated tabs and their respective preheated panels during the final phase of the cycle.

21. In the method as set forth in claim 20, including, the step of, distorting the bottom panel of the blank while simultaneously folding and sealing the opposite pairs of panels of the blank for efiectuating an overbreak of the bottom panel in erecting the blank into a carton.

22. In the method as set forth in claim 20, including, the step of, deflecting the tabs of the blank in planes forwardly of the planes of the related first named panels of the pair thereof.

23. In the method as set forth in claim 20, including, the step of, deflecting the first named panels of the blank in planes forwardly of the planes of the related tabs of the blank.

24. In the method as set forth in claim 20, including, the step of, momentarily overbending the glue tabs of the blank during the initial phase of the cycle.

References Cited in the file of this patent UNITED STATES PATENTS 2,169,311 Widell Aug. 15, 1939 2,350,874 Buxbaum June 6, 1944 2,423,870 Blessing July 15, 1947 2,516,624 Guyer July 25, 1950 2,829,569 Aquilla Apr. 8, 1958 2,844,077 Buhrke July 22, 1958 2,863,370 Dorfman Dec. 9, 1958 2,874,619 Phin Feb. 24, 1959 2,896,518 Gibb July 28, 1959 2,937,578 Dorfmann May 24, 1960 2,954,725 Palmer Oct. 4, 1960 2,970,525 Klein et a1 Feb. 7, 1961 2,995,991 Trelford Aug. 15, 1961 FOREIGN PATENTS 295,837 Germany Dec. 21, 1916 564,703 Canada Oct. 14, 1958 

